Tag Archives: bait

Nobody—not even an entomologist like me—wants to see critters in their home, office, school, or favorite restaurant. But see them we do. And unfortunately, the first reaction most people have is to reach for a can of bug spray and hose the place down.

But what does this really accomplish? Two things: a quick kill of only the critters you sprayed, and you’ve now left a coating of pesticides wherever you sprayed. Satisfied? Probably not, since your goal is to solve the problem, not just kill a few critters. If so, then put down the bug spray and walk away—slowly.

When we think of pests, we might imagine them as vile creatures that are intentionally tormenting us. The truth, however, is that pests are always there for a reason. Maybe they are inside because they found a gap leading to a safe place to spend the winter (think brown marmorated stink bug, ladybug, or boxelder bug). Or maybe your gutters are clogged and there is a moisture problem inviting to carpenter ants. Or you have overripe bananas with the stem torn at the top, exposing the fruit within, and now you see fruit flies. While it’s true that a spray might kill pests—so too can a swift shoe.

But if we want to develop a solution that addresses the issue and prevents future problems, we must follow two simple steps:

Inspection. Where are the pests found and how did they get there? It might feel like your whole house is infested, but with a thorough inspection you can often find the source of a problem by looking for where the critters or their evidence are most numerous. If you can find the source of where they are feeding or breeding, chances are you can do them in.

Identification. Knowing the identity of a pest tells you why it is there. It’s also a necessity for crafting a sound management plan. For example, this spring I received many calls about ants. Even when callers had tried sprays, they were ineffective. Why? Each pest is there for a different reason—and needs its own management approach.

Carpenter ants trailing on the outside of a building might be moving from outdoor parent nests to indoor satellite nests.

Case 1: Ants in Rental Home! Using a few pictures to determine size and the number of nodes, the ants were identified as carpenter ants, which do not actually eat wood. Instead, they excavate rotten wood to make their nests. This means carpenter ants indicate a moisture problem somewhere in the structure; an important problem you might not otherwise have known about. So in an oddball way, you owe them a debt of gratitude. And although parent nests are typically outdoors, satellite nests can be found inside buildings—so an inspection is needed to discover where the ants are living. This can be accomplished by baiting and tracking ants to the source, then eliminating the rotten wood and ant nest. For more details, see our carpenter ant fact sheet.

Case 2: Ants in Bathroom! These ants are identified by how they smell when crushed. Their name? The odorous house ant (abbreviated OHA). They build nests in moist locations and forage indoors for spilled foods.

Odorous house ants can move their entire colony or split into several colonies — making it tough to deal with them. (Credit: Janet Hurley)

Based on their biology, OHA can be difficult to manage because the colony is mobile—moving nest locations at will—and can actually split into multiple colonies if sprayed or for other reasons. To date, the best method to control OHA are certain baits that, when placed correctly, can be spread throughout the colony to achieve control.

Case 3: Winged Ants Indoors! Known as citronella ants by their smell, this species isn’t really a pest of homes because they don’t eat what we eat, nor are they at home indoors. Instead they live in the soil and feed on secretions from root-feeding insects. But they can be a nuisance when winged ants emerge into homes. Since their sole purpose in life is finding a new place to live, spraying or baiting are pointless. To avoid problems down the line, you’ll need to eliminate the cracks and crevices where ants are getting inside.

Foraging pavement ants bring bait back to the nest and spread throughout the colony. They’re a great target for baits.

After you’ve found where the pests really are and ID’d them correctly, you can a develop short-term plan to reduce their numbers and long-term solutions that fix the conditions that allowed or enticed them in in the first place.

Not fond of ants in the kitchen? You are not alone. And even after you’ve cleaned them up, washed the countertop, swept away the crumbs and taken out the garbage — they just keep coming, looking for more.

It’s this time of year when ants invade homes looking for food, water and shelter. Where are they coming from — and how are they getting there?

At 1/16 to 1/8 inch long, this is one tiny ant. Photo credit Joseph Berger.

A number of ant species seem to specialize in homes. Among the most tenacious: the odorous house ant, Tapinoma sessile. You can tell it by its smell. Just crush it in your fingers and give it a sniff.

What’s that smell? Some say it’s the smell of rotting coconut, but how many of us know the pleasure of a rotting coconut? Just call it pungent.

Odorous house ants are well adapted to the urban environment. In fact, being around man-made structures allows them to become the dominant ant species with enormous interconnected colonies. They invade homes and apartments through the smallest cracks and gaps, foraging for sweets. So keeping them out may be near impossible.

Pesticides and insecticidal ant baits are the most common forms of ant control. In IPM we almost never recommend spraying over other sound tactics. In the case of odorous house ants, spraying the foundation and soil around a structure can help. But it can also kill non-target insects.

Plus — it rarely kills the queen (an urban supercolony may have scores; even hundreds) and the colony might well live on.

Baiting for odorous house ants with sweet gel baits is an effective way to reduce the whole colony. Adult ants carried them back to the nest and fed to the larvae and queens — the beating heart of the colony.

You might choose to hire a professional who will identify the ant species (very important for baiting correctly) and place bait where ants are active. Or you might decide to use sweet boric acid bait from the hardware store. Either way there’s a critical step here.

If the odorous house ants accept the bait, more and more ants will show up for the feast. The more ants, the more bait they will transfer back to the larvae and queens. Let the party rage on! You could see dozens of ants, maybe hundreds.

Ignore them until at least the following day — and never spray an insecticide or cleanser on or near the bait. With professional-use baits, the disappearance of ants is quite dramatic. Boric acid baits will take a bit longer but are no less effective.

As always, before you use a pesticide, read the label and follow instructions. Once the party is over, clean up the remains with soap and water.

And remember, ants are like a sanitation department. They forage on what we leave behind, so keep those counters (and the sink, garbage can, compost bucket, microwave…) clean and free of food spills and crumbs. We best coexist with ants when we don’t invite them inside.

Pavement ants are one of the most common indoor ant pests in the northeastern United States. These small brown or brownish-black ants make their nests under building foundations, sidewalks, patios or rocks — leaving characteristic mounds of soil nearby. Do they come inside? Oh, yes. You’ll find them indoors when they forage for sweets and high-protein foods — mostly at night.

Pavement ants are common indoor pests. They are usually noticed around sidewalks and stone work.

Did you know …?

Ant Fight: In the spring, neighboring pavement ant colonies sometimes duke it out on the sidewalk, killing hundreds of their neighbors.

Full House: Pavement ant colonies can have as many as 10,000 workers in a single nest.

Follow Me! Pavement ants use a chemical or pheromone trail to recruit nest mates to a food source.

Many ant species create nests in the ground, excavating soil in the process. Nests are often under or on sides of rocks, sidewalks, or cement slabs — which buffer them against temperature extremes.

For instance, when you see tiny ants going back and forth to the same crumbs or splashed grease, clean the counter. Not only are you depriving them of food, you’re also wiping away that invisible pheromone trail.

If you put bait out, be sure you get the right one. A bait formulated for carpenter ants, for instance, won’t help you much.